1. Field of the Invention
The invention relates to a device for exposure of a mask pattern on a surface of a continuous workpiece of great length (hereinafter called a xe2x80x9cstrip-shaped workpiecexe2x80x9d), such as a film of organic compound, a lightweight metal or the like.
2. Description of Related Art
To form several different electronic components or the like on a strip-shaped workpiece, such as a film of organic compound, a lightweight metal or the like, an exposure process is performed in which a rolled strip-shaped workpiece is unrolled off a reel, transported and stopped for each predetermined pattern area, where a mask and the respective exposure area of the strip-shaped workpiece are positioned relative to one another, and afterwards a mask pattern is exposed onto the workpiece.
The strip-shaped workpiece used in the above described exposure process, conventionally, has a length of 100 m. It is transported by the workpiece being unrolled from the state rolled on the reel, exposed and wound again onto a reel. A light-sensitive resin, such as a resist, a photosensitive polyimide or the like is applied to the strip-shaped workpiece.
For exposure onto a strip-shaped workpiece, the reel, which has been wound with the strip-shaped workpiece, is located in a feed roll portion. The strip-shaped workpiece is clamped between a transport rotary roll and a pressure roll. By turning the rotary roll, it is delivered to the exposure portion.
In the exposure part, the strip-shaped workpiece is attached by vacuum in a workpiece carrier. Exposure light is emitted by a light irradiation portion, via the mask and a projection lens, onto the strip-shaped workpiece. The mask pattern, which has been formed on the mask, is exposed. After completion of exposure, the strip-shaped workpiece is released from the workpiece carrier. The rotary roller turns, and the strip-shaped workpiece is transported to the next exposure area.
The completely exposed strip-shaped workpiece is wound onto a reel which is located in a take-up roll portion.
Conventionally, the strip-shaped workpiece has a width of roughly 125 mm. Other strip-shaped workpieces were located next to one another in a row, and thus, a product was produced. Therefore, exposure was also sufficient when the mask pattern was exposed in a row.
But recently, there have been cases in which the width of the strip-shaped workpiece is large, i.e., for example, 250 mm, and in which two rows of mask patterns are to be exposed next to one another on the strip-shaped workpiece, so that more products can be produced from a roll of strip-shaped workpiece. Therefore, there is a demand for exposure of the mask pattern in two rows.
If, in a conventional device, an effort is made to expose two rows of mask patterns on a strip-shaped workpiece, the strip-shaped workpiece is transported by the reel located in the feed roll portion and first a mask pattern is exposed in the first row. After completion of the exposure of the first row the strip-shaped workpiece is wound up by a reel located in the take-up reel portion.
For exposure of the second row, the reel, onto which the strip-shaped workpiece with a first row which has already been completely exposed has been wound, is removed from the take-up roll portion and installed in the feed roll portion, i.e., the reels are interchanged. The strip-shaped workpiece is transported again by the reel and the second row is exposed.
The completely exposed strip-shaped workpiece is taken up by the reel installed in the take-up roll portion. For exposure of the second row, the same device can be used by which the first row was exposed, or also another device can be used.
Conventionally, as was described above with respect to a roll of workpiece, between starting of exposure and its completion, a process of manual xe2x80x9creel changingxe2x80x9d has always arisen, causing efficiency to be poor.
When a mask is being prepared in which two rows of patterns are formed, a projection lens with twice the projection surface is prepared and the two rows are exposed together, and a roll workpiece can be exposed without xe2x80x9creel changing.xe2x80x9d But, an enormously large projection lens is required for this purpose. The material of a large lens is very expensive. The entire exposure device also becomes larger.
The invention was devised to eliminate the above described defects in the prior art. Therefore, a primary object of the present invention is to devise an exposure device for a strip-shaped workpiece in which several rows of mask patterns can be exposed onto a strip-shaped workpiece without the device becoming larger and without the rolls having to be exchanged.
The object is achieved in accordance with the invention as follows:
(1) In a exposure device in which patterns formed on a mask are exposed in steps onto a strip-shaped workpiece, there are a workpiece transport device for transport of the strip-shaped workpiece on a workpiece carrier in the lengthwise direction of the strip-shaped workpiece and a workpiece movement device which moves the strip-shaped workpiece on the workpiece carrier in the direction of width of the strip-shaped workpiece. A control member controls the workpiece transport device and the workpiece movement device. Transport of the strip-shaped workpiece and its movement in the direction which orthogonally intersects the transport direction are repeated. Several rows of mask patterns are exposed on the strip-shaped workpiece. In this way, several rows of mask patterns can be exposed onto a roll strip-shaped workpiece without the need to replace the rolls, without the device being made especially large and without a large projection lens with an enormous cost having to be used.
(2) A roll portion movement device is put in place; it moves a feed roll portion for arranging the strip-shaped workpiece before exposure and a take-up reel portion for arranging the strip-shaped workpiece after each exposure in the direction of the width of the strip-shaped workpiece. During transport of the strip-shaped workpiece, the strip-shaped workpiece is moved by the roll portion movement device in the direction of width such that there is no twisting in the strip-shaped workpiece.